In order to use a wire such as a superconducting wire in a device, there is an increasing demand for a connection technique for connecting wires with solder. For example, PTL 1 discloses a connection device 100 which connects superconducting wires together (see FIG. 5). The connection device 100 includes a lower pressing and heating plate 101B provided with a wire accommodation groove 102 having substantially the same width as that of a wire, and an upper pressing and heating plate 101A provided with a protrusion 112A having a slightly smaller width than that of the wire accommodation groove 102, and is configured so that the opening of the lower pressing and heating plate 101B is covered with the upper pressing and heating plate 101A by an opening and closing mechanism 108 and thus heating and pressing can be performed on the wire. When the wires are bonded together, the end portions of the wires are accommodated in the wire accommodation groove 102 in an overlapping manner with solder interposed therebetween, and as pressing together and heating are performed by the lower pressing and heating plate 101B and the upper pressing and heating plate 101A, the solder is melted to connect the superconducting wires.
Since the connection device 100 is used, an operator does not need to melt the solder by using a soldering iron in order to connect the superconducting wires. That is, it is possible to form a splice structure that exhibits stable connection performance regardless of the skill of the operator.